Bead tray method and apparatus for yarn purification



Dec. 6, 1955 E. M. HICKS, JR

BEAD TRAY METHOD AND APPARATUS FOR YARN PURIFICATION Filed Aug. 11 1949 ktrsii X X XXXX z x x x x x X XX INVENTOR. ELIJA M4X1E'HICIQJR,

syd xwdmw ATTORNEY United States Patent 'BEAD TRAY METHOD AND APPARATUS FOR YARN PURIFICATION Elija Maxie Hicks, Jr., Old Hickory, Tenn, assignor to E. I. du Pont 'de Nemours & Company, Wilmington, Del., a corporation of Delaware Application August 11, 194% Serial No. 109,642

5 Claims. (Cl. 8-151.2)

quently passed through a softening or demineralizing process. Yarn processed in package form, i. e., bucketcakes or bobbins in which form the yarn is collectedin the acid state, requires in the neighborhood of 20-40 gallons of soft water to wash one pound of such yarn acid free. If the yarn is handled on-the-run as, for example, on an advancing reel, this water consumption is usually even higher, for instance as'much as 50 or 60 gallons per pounds of yarn. In one instance, Burkholder et al., U. S. Patent 2,272,182 involving an improved method for washing yarn on an advancing reel, there is shown a washing of 150- denier 40-filament yarn which requires but about 23 gallons of water per pound of yarn. Even still further reduction is desired for more economic production. From these figures it is apparent that washing and purification of viscose rayon yarn is a very real item in the cost of viscose rayon yarn manufacture and further economy is desired.

It is, therefore, an object of this invention to provide a novel apparatus for washing and purifying yarn on-therun, especially viscose rayon yarn, which apparatus greatly reduces the amount of liquid needed for washing, desulfuring bleaching or otherwise treating the yarn. Other objects will be apparent hereinafter.

The objects of this invention are accomplished by the use of a tray, preferably arched, containing in closely packed form, a plurality of spherical bodies. The traveling strand runs over this tray repeatedly in and out of contact with the spherical bodies but always in contact with treating liquor which is usually directed against the yarn from sprays situated above the yarn. There is a rapid exchange between the treating liquor, such as wash water, and the liquids or impurities in the yarn. Fast, effective treatment is thereby obtained.

The invention will be better understood by reference to the figures which are given for illustrative purposes only and of which:

Figure 1 is a plan view of the tray and guide rolls,

Figure 2 is a side view and Figure 3 is an end view.

The tray is composed of a bottom 2, sides 3 and end plates 4. Bottom 2 is preferably curved as an arc of a circle with a radius of 2 or 3 feet or more or less depending on the length of the tray. Other curvature than that described above may be used. For example, the tray may be made to approximate a circle or two of the trays shown in the figures may be placed together in the vertical plane. The tray may be flat bottomed and it is also possible to make the tray of two inclined planes back to back. However, in the flat bottomed tray and angled trays more care is involved in providing means to insure good contact of the yarn with the feeds during processing. Accordingly, the arched trays are preferred. yarn or article being processed is fed tangentially to and from the tray and it follows the arch of the tray in inti-. mate contact with the beads and treating liquids.

As shown in Figure 2, at both ends are drains or pipes 5. The tray is filled with beads or marbles 6. These spherical bodies are present in suificient number to form substantially one full layer as shown in the figures. One layer of the heads is usually sufficient. The beads may vary considerably in diameter but preferably they are all of the same relatively small diameter, as for example, a diameter of /z inch. Beads of inch diameter and up to 1 inch diameter may be used and are preferred. While beads larger in diameter may be used, it is preferred to use the smaller beads for the greater exchange of solution that is afforded. Beads having diameters less than inch are more diflicult to handle. The beads need not be placed on the tray in any particular manner. They are poured onto the tray and in seeking a level they fall into an appropriate arrangement such as is shown in the figures. It is generally desired to have the tray substantially full of beads to get the maximum scrubbing effect. Should a few beads be missing, they are easily replaced by merely dropping a few beads in at the midpoint, that is at the maximum elevation of the tray. Instead of beads a surface having embossed, spherical projections could be used as could cylindrical rods. However, free rotatable spheres are preferred because they are easily replaced, transferred, cleaned and because of the tracking they afiord.

Located at the ends of the tray are suitable driven rollers or guides 7. Situated above the tray are sprays 8--the location of which is not critical. They are, of course, placed for the most efiicient spraying. In operation a yarn 9 is passed from the driven roller or guide 7 across the top of the tray to the guide 7 at the other end of the tray from where it is passed to a suitable windup device not shown. As shown in Figures 1 and 3 a plurality of continuous strands or yarns may be processed at one time in the form of a warp. As the yarns travel across the tray the various sprays 8 direct a treating fluid onto the yarn and beads 6. The treating fluid, shown by the dotted lines 10, may vary in composition from spray to spray or the same fluid may be used in all sprays. Gen erally, it is preferred to use for any one tray one particular liquid. The liquid collects in the tray and is held to some. extent by surface tension in the interstices formed by the beads. As fresh wash is added, it replaces the spent or partially spent wash which drains ofi through the pipes 5 for recovery or recycling. As shown in Fig ures 1 and 3 each strand contacts in its passage across the tray a plurality of beads the contact-being made on various sides of the yarn. The beads serve as a guiding means and as the yarns run across the tray, they rub first on one side and then on the other. Also at various places they are out of contact with the beads and in contact only with the treating liquid. The strands imbibe liquid which is rubbed off by contact with the beads, they again imbibe fresh liquid which is again almost immediately rubbed off and the process is repeated a large number of times. In this way a very rapid exchange of Water and solution to and from the running yarn is effected. The top surfaces of the yarn are, of course, directly sprayed and exchange on those surfaces is rapid and effective.

In a specific illustration, it was found that -denier 60-filament bright viscose rayon yarn with no twist running at a speed of 92 yards/minute could be washed in 1.7 seconds with soft water heated to 30 C. or to 65 C. At a speed of yards/minute and with soft water heated to a temperature of 65 C., the time needed to obtain acid-free yarn was 1.4 seconds. As expected, the time In the arched trays the of treatment is slightly longer in case there is a small amount of twist in the yarn. For example, with a twist of 0.1 turns/inch, the washing time is lengthened from 1.7 to 2.1 seconds.

In numerous tests made with this apparatus, it was found that actual water consumption was of the order of 5-10 gallons/lb. of yarn, which is indeed surprising, for all other methods of washing known to me require several times this amount of water or other processing liquid.

For example, under comparable conditions in washing 150-denier yarn the apparatus and process of this invention gave results far superior to those obtained by conventional package washing:

The foregoing figures are given by way of illustration and are not intended to be limitative. Yarn speeds of 300 or 400 or even more yards/minute may be used with satisfactory results and the wash water or other treating liquid may be at any temperature desired, as for example from below room temperature up to the boiling point. The time for Washing is not influenced much by the water temperature nor do slight changes in tension produce any noticeable efiect on the time of washing. The tension applied to the yarn may be varied widely and may be of the order of 5 grams up to 30 or 40 grams on ISO-denier yarn or from 0.03-0.3 gram/ denier. Preferably the yarn should be free of twist or have only a very small amount of twist, but yarns with a twist of 2 or 3 turns/inch or more can be processed on this apparatus at a much slower rate of purification.

The bead tray of this invention may be of any convenient size. Small trays may be used and a single end can be directed over the rolls 7 so as to make several passes over the beads. It is preferred, however, to use a continuous tray with a warp sheet of threads being washed in one pass. In another embodiment several individual trays arranged one over the other may be used. Each of these may be provided with separate drains. Such an arrangement is advantageous in instances where several difierent washes or treating liquors are being used. Further, the trays may be used in tier fashion or they may be placed end-to-end to effect continuous processing.

While this invention has been described with particular reference to yarn, it is not limited thereto. The apparatus of this invention may be used in the processing of rods, tubes, ribbons, etc., that is, anything of essentially yarn-like dimensions and flexibility or broadly speaking, a traveling strand.

The apparatus and process of this invention afiords definite advantages over previously known purification methods. Far less materials are needed and purification is accomplished in shorter times. Decided economic gains are accomplished. Purification is accomplished with converged yarn. There is no need to separate the yarn bundle. Danger of loops and poor yarn quality usually resulting in diverged filament Washing are avoided. The nature of the pattern of close-packed spheres provides regular spacing of yarn on centers equal to half the diameter of the spheres, thereby positioning the threads without the use of guides. While the yarns follow the grooves formed by the lay-down of the spheres in the close-packed configuration, they travel in a substantially straight path. The yarns may be purified under relatively high tensions, with or without twist, with no adverse eifect upon purification rate using high speeds of up to 25 0 to 450 yards per minute.

Any departure from the procedure described herein which conforms to the principles of the invention is intended to be included within the scope of the claims below.

I claim:

1. An apparatus for washing a traveling yarn which comprises an arched tray, the upper surface of which is substantially covered with a monolayer of adjacently disposed, rotatable, rigid spheres, means to move the yarn over and in contact with the exposed surfaces of said spheres and means to continuously direct a washing fluid against the area of yarn and sphere contact and remove spent fluid.

2. A process for washing a traveling yarn which comprises moving said yarn in contact with the exposed surface of a fixed, arched tray-supported monolayer of rotatable, rigid spheres; the motion of said yarn being across the arched length of said tray, while continuously directing washing fluid into the area of yarn and sphere contact and removing spent fluid.

3. The process of claim 2 wherein the yarn is viscose rayon.

4. The process of claim 3 wherein the washing fluid is water.

5. The process of claim 4 wherein the washing fluid is directed into the area of web and sphere contact by spraying.

References Cited in the file of this patent UNITED STATES PATENTS 164,785 Wekey et a1 June 22, 1875 388,078 Sedgwick Aug. 21, 1888 443,464 Sedgwick Dec. 23, 1890 1,203,306 Brinkman Oct. 31, 1916 1,913,601 Leppin June 13, 1933 1,916,946 Fruh July 4, 1933 1,948,568 Faber et a1 Feb. 27, 1934 1,963,956 Craig June 26, 1934 2,041,338 Harrison May 19, 1936 2,053,293 Long Sept. 8, 1936 2,070,716 Dreyfus Feb. 16, 1937 2,176,307 Lamb et al Oct. 17, 1939 2,520,594 Costa Aug. 29, 1950 2,533,167 Kilham Dec. 5, 1950 2,542,819 Kropa Feb. 20, 1951 FOREIGN PATENTS 226,213 Germany Oct. 1, 1910 

1. AN APPARATUS FOR WASHING A TRAVELING YARN WHICH COMPRISES AN ARCHED TRAY, THE UPPER SURFACE OF WHICH IS SUBSTANTIALLY COVERED WITH A MONOLAYER OF ADJACENTLY DISPOSED, ROTATABLE, RIGID SPHERES, MEANS TO MOVE THE YARN OVER AND IN CONTACT WITH THE EXPOSED SURFACES OF SAID SPHERES AND MEANS TO CONTINUOUSLY DIRECT A WASHING FLUID AGAINST THE AREA OF YARN AND SPHERE CONTACT AND REMOVE SPENT FLUID.
 2. A PROCESS FOR WASHING A TRAVELING YARN WHICH COMPRISES MOVING SAID YARN IN CONTACT WITH THE EXPOSED SURFACE OF A FIXED, ARCHED TRAY-SUPPORTED MONOLAYER OF ROTATABLE, RIGID SPHERES; THE MOTION OF SAID YARN BEING ACROSS THE ARCHED LENGTH OF SAID TRAY, WHILE CONTINOUSLY DIRECTING WASHING FLUID INTO THE AREA OF YARN AND SPHERE CONTACT AND REMOVING SPENT FLUID. 